Feasibility of Quantum Communications in Aquatic Scenarios

Abstract Exchanging information in the aquatic environment represents a challenging but yet necessary task for example in military and scientific applications. Quantum cryptography is an already available solution able to guarantee information theoretic secure communication in multiple environment, i.e. free-space, fiber and space link. Yet, the implementation of quantum communications in the aquatic scenario is still a relatively new and unexplored field of research. This paper provides a feasibility analysis of various quantum key distribution protocols simulated in the water medium, by performing an evaluation of their secret key rate, external noise sources and wind effect on the surface of the water. Three different links are considered: line-of-sight, non line-of-sight and free-space to underwater channels. The outcomes of this analysis suggest that underwater quantum communication can be implemented by adopting several protocols in all three scenarios.